A bus departure schedule optimization method considering multi-bus line transfer in charging station

Abstract

The application discloses a kind of bus departure timetable optimization method considering multiple bus lines transfer in charging station, first input and electric bus charging transfer various parameters, with cost-related various parameters;Second, the charging demand of each vehicle and the passenger transfer demand between each line are calculated, and the selection constraint of electric bus charging station and the charging transfer constraint in charging station are established;Finally, with the minimum bus operation cost and the maximum transfer passenger number as objective function, with bus scheduling scheme and the departure timetable of each line bus as decision variable, the bus scheduling model of multiple bus lines transfer in charging station is established.The application can meet the charging demand of bus and the passenger transfer demand in charging station simultaneously by reasonably scheduling the bus needing charging according to certain departure time, can increase the attraction of bus charging to transfer passengers, and promote the electrification process of urban bus.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of intelligent transportation, and relates to the field of dynamic scheduling of urban bus routes, and more particularly to a bus departure schedule optimization method considering multiple bus line transfers in a charging station. BACKGROUND

[0002] Electric buses have been adopted by countries around the world because they can achieve zero emissions of pollutants, and the complete popularization of electric buses has become a future development trend of public transportation. However, electric buses need to be charged midway due to the limitation of battery capacity. In order to charge the buses, related charging infrastructure is currently deployed near each line. In addition, how to ensure efficient passenger transfer and minimize passenger detour distance is also a key problem to be solved in bus scheduling.

[0003] Therefore, the application proposes a bus departure schedule optimization method considering multiple bus line transfers in a charging station, which allows electric buses to enter a charging station for charging at a midway station, and uses a battery replacement mode in the charging station to improve the utilization rate of vehicles, energy and charging piles. In addition, in order to meet the needs of bus charging and passenger transfer at the same time, the departure schedule is optimized so that the above two processes are carried out at the same time in the charging station to maximize the demand for both. How to arrange the scheduling of charging vehicles and the transfer of passengers on each line, establish the charging station selection constraints of buses and the bus transfer model in the charging station, is the key problem to be solved by the patent.

[0004] Through literature retrieval of existing technologies, it is found that most of the literature does not consider the problem of vehicle charging and passenger transfer in the charging station at the same time, and the optimization of the departure schedule is mainly aimed at the passenger transfer scene of the bus station, lacking research on the optimization of the departure schedule of the multiple line bus transfer scene in the charging station. SUMMARY

[0005] Technical problem: In view of the deficiencies of existing research, the purpose of the application is to provide a bus departure schedule optimization method considering multiple bus line transfers in a charging station, according to the charging demand of electric buses and the transfer demand of passengers, by reasonably arranging the charging scheduling of each station and the transfer plan in the charging station, to maximize the satisfaction of bus charging demand and passenger transfer demand as the target, to determine the bus departure schedule and charging scheduling scheme.

[0006] Technical solution: In order to solve the above technical problems, the application provides a bus departure schedule optimization method considering multiple bus line transfers in a charging station, including the following steps:

[0007] Step 1: input parameters related to electric bus charging transfer, including initial electric quantity of the bus, energy consumption value between initial bus station and the rest bus stations of the line, passenger demand of the first vehicle of each line, location of the charging transfer station, transfer time limit, passenger arrival rate, distance between adjacent bus stations, distance between each bus station and the charging transfer station, average driving speed of the electric bus, input parameters related to cost, including unit distance operation cost of the bus, unit passenger loss cost of the transfer;

[0008] Step 2: according to the initial electric quantity of each vehicle and the energy consumption value between the initial bus station and the rest bus stations of the line, the charging demand of the vehicle arriving at each bus station is calculated, and the bus station selection constraint of the vehicle charging is established;

[0009] Step 3: according to the total passenger transfer demand between each bus line in the research period, the function relationship between the passenger quantity of each line and the departure interval, the passenger transfer demand quantity of each vehicle of the line and the rest lines is calculated, the time of the vehicle arriving at the corresponding charging station is calculated on the basis of the charging scheduling in step 2, and the passenger transfer model between each bus line in the charging station is established through the time range constraint of the bus transfer;

[0010] Step 4: taking the minimum bus operation cost and the maximum passenger number as the objective function, taking the vehicle scheduling scheme and the bus departure timetable of each line as the decision variable, the bus scheduling model of the transfer of multiple bus lines in the charging station is established.

[0011] In the application, step 1 includes the following steps:

[0012] Input parameters related to electric bus charging transfer, including: using N i to represent the electric bus set of line i, using K i to represent the station set of line i, using P to represent the charging station set, using to represent the initial electric quantity of the bus, the unit is kwh, the electric bus battery capacity Q, the unit is kwh, the minimum charging threshold δ, the energy consumption value between the initial bus station and the rest bus stations k on line i , the unit is kwh, the passenger arrival rate λ ij between line i and line j, the unit is person / min, the passenger demand D i1,j of the first vehicle on line i to line j, the unit charging time t b , the unit is min, the distance between the initial bus station and the rest bus stations k on line i , the unit is km, the distance between the bus station k and the charging transfer station p on line i , the unit is km, the average driving speed v of the electric bus, the unit is km / h, the maximum departure interval hmax , unit is min, minimum headway h min , unit is min, input and cost-related parameters, bus unit distance operation cost C1, unit is yuan / km / kwh, unit transfer passenger loss cost C2, unit is yuan / person;

[0013] In the application, according to the initial electric quantity of each vehicle, the energy consumption value between the initial bus station and the rest bus stations of the line, the charging demand quantity of the vehicle arriving at each bus station is calculated, the bus station selection constraint and the charging station selection model of the vehicle charging are established, including the following steps:

[0014] The bus station and charging station selection constraint of the vehicle charging is established, as shown in formula (1)-(2):

[0015]

[0016]

[0017] wherein, is a binary variable, indicates that the vehicle n on the line i selects to charge at the station k to the charging station p for transfer, and vice versa, in formula (2), indicates the energy consumption from the starting point to the ending point of the line i, unit is kwh;

[0018] In the application, according to the total transfer demand of passengers among each bus line in the research period, the function relationship between the transfer passenger quantity of each line and the headway, the passenger transfer demand quantity of each vehicle of the line and each line is calculated, on the basis of charging scheduling, the time of the vehicle arriving at the corresponding charging station is calculated, through the time length range constraint of bus transfer, the passenger transfer model among each bus line in the charging station is established, including the following steps:

[0019] Step 31: according to the relationship between the vehicle departure time and the headway, the departure time of each vehicle of each line is calculated, as shown in formula (3)-(5):

[0020]

[0021]

[0022]

[0023] In formula (3), indicates the departure time of the vehicle n on the line i, unit is min, indicates the departure time of the first vehicle on the line i, unit is min, h ikis the headway between vehicle n-1 and vehicle n on route i, in min, formula (4) represents the departure time range of the first vehicle on route i, formula (5) represents the departure time range of the last vehicle on route i, T represents the study period, in min;

[0024] Step 32: The bus departure schedule needs to meet the constraint of the maximum and minimum headway, the headway of each vehicle on each route is calculated, and the headway is constrained, as shown in formula (6):

[0025]

[0026] Step 33: Determine whether the vehicle is charging, if the vehicle is charging, calculate the time when the vehicle arrives at the charging station, as shown in formulas (7)-(12):

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033] wherein, is a binary variable used to linearize the if statement, M is a very large positive number, represents the time when vehicle n on route i arrives at charging station p from station k, in min, in formula (12), represents the time when vehicle n on route i arrives at charging station p, in min;

[0034] Step 34: According to the relationship between transfer passengers and headway and the arrival rate of transfer passengers, calculate the passenger demand of vehicle n on route i that needs to transfer to route j, as shown in formulas (13)-(14):

[0035]

[0036]

[0037] In formula (13), d in,j represents the passenger demand of vehicle n on route i that needs to transfer to route j, in formula (14), d i1,j and D i1 , jdenotes the passenger demand of the first vehicle on line i needs to transfer to the vehicle on line j, d i1,j is a variable, D i1,j is a parameter;

[0038] Step 35: According to the time of each vehicle arriving at the charging station p, it is judged whether the vehicle n on line i and the vehicle m on line j successfully transfer at the charging station p, as shown in formulas (15)-(20):

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] wherein, is a binary variable, denotes that the vehicle n on line i transfers to the vehicle m on line j at the charging station p, and vice versa, is a binary variable, which is used for linearization of if statement, is a binary variable, which is used for linearization of "or" relationship, and ∈ represents a very small positive number;

[0046] Step 36: According to the bus transfer conditions of each line in step 35, the passenger quantity of the vehicle n on line i transferring to the bus line j at the charging transfer station is calculated, as shown in formulas (21)-(23):

[0047]

[0048]

[0049]

[0050] wherein, r in,j denotes the passenger quantity of the vehicle n on line i transferring to the bus line j at the charging transfer station, r i,j denotes the passenger quantity of the vehicle on line i transferring to line j;

[0051] In the present application, step 4 comprises the following steps:

[0052] Step 4: With the objective function of minimizing bus operating costs and maximizing the number of transfer passengers, and with the vehicle scheduling scheme and the departure time of each bus route as decision variables, establish a passenger transfer and bus scheduling model between bus routes within the charging station. The objective function is shown in formula (24):

[0053]

[0054] Compared with the prior art, the present invention has the following advantages:

[0055] This invention addresses the issues of charging electric buses and passenger transfers on various routes in cities. It proposes to simultaneously meet the needs of charging and transfers at charging stations by optimizing departure timetables and scheduling charging buses, thereby increasing the attractiveness of electric bus charging to transfer passengers and promoting the electrification of public transportation. Attached Figure Description

[0056] Figure 1 This is the overall flowchart of the present invention;

[0057] Figure 2 A schematic diagram showing the locations of bus stops and charging (transfer) stations for each route. Detailed Implementation

[0058] The following is in conjunction with the appendix Figures 1-2 The present invention will be further described in detail with reference to the examples and embodiments, but the implementation of the present invention is not limited thereto. The implementation of the present invention is not limited to the examples described, and any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and are included within the protection scope of the present invention.

[0059] Example 1

[0060] Taking Line A and Line B as the research objects, the distance between adjacent stations is 500m, as shown in the attached figure. Figure 2 As shown, the two lines are parallel, with a distance of 1 km between them. The charging transfer station p1 is located at the center of the two lines. The distances from the bus stops on each line to the charging transfer station are shown in Table 1. Within the study period T = 60 min, the departure frequencies on lines A and B are 6 vehicles / h and 7 vehicles / h, respectively, i.e., N A =6, N B =7, the battery swapping time of the vehicle at the charging station is t. b =3min, maximum departure interval h max =6min, minimum departure interval h min =15min; the average speed of the electric bus is v = 20km / h, the bus battery capacity is Q = 180kWh, the minimum charging threshold is δ = 0.2, and the energy consumption value between the initial bus stop and the remaining bus stops k on route i is... As shown in Table 2, the initial energy of vehicle n on line i As shown in Table 3, the arrival rate λ ij respectively, λ AA = 0 person / min, λ AB = 3.5 person / min, λ BA = 2.9 person / min, λ BB = 0 person / min, the passenger demand D i1 , j of the first vehicle on line i needs to transfer to the passenger on line j D A1,A = 0 person, D A1,B = 16 person, D B1,A = 15 person, D B1,B = 0 person; the bus unit distance operation cost C1 = 150 yuan / km / kwh, the unit transfer passenger loss cost C2 = 100 yuan / person.

[0061] Table 1: The distance from each line bus station to the charging transfer station

[0062]

[0063] Table 2: The energy consumption value from the initial bus station of each line to the rest bus stations

[0064]

[0065] Table 3: The initial energy of each vehicle of each bus line

[0066]

[0067] Example 2

[0068] According to steps 2, 3, 4, formula (1)-(23) and objective function formula (24), the vehicle charging scheduling scheme and the passenger transfer scheme of each line of example 1 are calculated, and the results are shown in Table 4. At the same time, the departure timetable of each line bus is obtained, and the results are shown in Table 5.

[0069] Table 4: Vehicle charging scheduling and passenger transfer scheme of each line

[0070] Line A vehicle number Charging bus stop Transfer vehicle Line B vehicle number Charging bus stop Transfer vehicle 1 3 B2 2 3 A1 4 3 B3 3 3 A4 5 3 B5, B6 5 3 A5 6 3 B7 6 2 A5 - - - 7 3 A6

[0071] Table 5: Departure timetable of each line bus

[0072] Line vehicle number A1 A2 A3 A4 A5 A6 - Departure time (min) 6 12 18 27 42 57 - Line vehicle number B1 B2 B3 B4 B5 B6 B7 Departure time (min) 3 9 24 30 39 45 60

[0073] By applying the method of the present application, the value of the objective function C is 72389 yuan.

Claims

1. A method for optimizing bus departure schedules considering transfers between multiple bus lines within a charging station, characterized in that, The method includes the following steps: Step 1: Input the parameters related to electric bus charging and transfer, including the initial battery level of the bus, the energy consumption between the initial bus stop and the other bus stops on the route, the transfer passenger demand of the first bus on each route, the location of the charging and transfer station, the transfer time limit, the transfer passenger arrival rate, the distance between adjacent bus stops, the distance between each bus stop and the charging and transfer station, and the average speed of the electric bus. Input the parameters related to cost, including the bus unit distance operating cost and the unit transfer passenger loss cost. Step 2: Based on the initial battery level of each vehicle and the energy consumption value between the initial bus stop and the other bus stops on the route, calculate the charging demand of the vehicle at each bus stop and establish bus stop selection constraints for vehicle charging. Step 3: Based on the total passenger transfer demand between each bus route during the study period, the functional relationship between the number of transfer passengers on each route and the departure interval, calculate the passenger transfer demand between each bus on the route and the other routes. Based on the charging scheduling in Step 2, calculate the time for vehicles to arrive at the corresponding charging station. Through the time range constraint of bus transfer, establish a passenger transfer model between each bus route within the charging station. Step 4: With minimizing bus operating costs and maximizing the number of transfer passengers as the objective functions, and using vehicle scheduling schemes and bus departure schedules for each route as decision variables, establish a bus scheduling model for multiple bus route transfers within the charging station.

2. The method for optimizing bus departure schedules considering multiple bus line transfers within a charging station as described in claim 1, characterized in that... Step 1 includes the following steps: Input the parameters related to electric bus charging and transfer, including: using N i Let K represent the set of electric buses for route i. i Let P represent the set of stations for line i, and let P represent the set of charging stations. The initial battery capacity of the bus (in kWh), the electric bus battery capacity Q (in kWh), the minimum charging threshold δ, and the energy consumption between the initial bus stop and other bus stops k on route i are all represented. The unit is kWh, and the transfer passenger arrival rate λ between line i and line j is... ij The unit is people / min, and the passenger demand D for transferring from the first train on line i to line j. i1,j Unit battery swapping time (t) b The unit is min, representing the distance between the initial bus stop on route i and the remaining bus stops k. The unit is km, and the distance between bus stop k and charging transfer station p on route i is... Units are km, average speed v of electric buses (km / h), and maximum departure interval (h). max The unit is min, minimum departure interval h. min The unit is min. Input the various cost-related parameters: bus unit distance operating cost C1, unit is yuan / km / kwh, and unit transfer passenger loss cost C2, unit is yuan / person. Step 2 includes the following steps: Based on the initial battery level of each vehicle and the energy consumption value between the initial bus stop and the other bus stops on the route, calculate the charging demand of the vehicle when it arrives at each bus stop, and establish the selection constraints of bus stops and charging stations for vehicle charging. in, For binary variables, This indicates that vehicle n on route i chooses to travel from station k to charging station p for charging and transfer, and vice versa. In formula (2), This represents the energy consumption from the starting point to the end point of line i, in kWh. Step 3 includes the following steps: Step 31: Based on the relationship between vehicle departure time and headway, calculate the departure time of each vehicle on each route, as shown in formulas (3)-(5): In formula (3), This represents the departure time of vehicle n on route i, in minutes. This represents the departure time of the first bus on route i, in minutes and hours. in The headway between vehicle n-1 and vehicle n on line i is expressed in min. Formula (4) represents the departure time range of the first vehicle on line i. Formula (5) represents the departure time range of the last vehicle on line i. T represents the study period in min. Step 32: The bus departure timetable must meet the constraints of maximum and minimum headway. Calculate the headway for each bus on each route and impose constraints on the headway, as shown in formula (6): Step 33: Determine if the vehicle is charging. If the vehicle is charging, calculate the time it takes for the vehicle to arrive at the charging station, as shown in formulas (7)-(12): in, This is a binary variable used to linearize the if statement; M is a very large positive number. This represents the time it takes for vehicle n on line i to travel from station k to charging station p, in minutes. In formula (12), This represents the time it takes for vehicle n on route i to arrive at charging station p, in minutes. Step 34: Based on the relationship between transfer passengers and headway and the arrival rate of transfer passengers, calculate the passenger demand for transfer from vehicle n on line i to line j, as shown in formulas (13)-(14): In formula (13), d in,j This represents the passenger demand for transferring from vehicle n on line i to line j. In formula (14), d i1,j and D i1,j This represents the passenger demand where the first train on line i needs to transfer to line j, d i1,j As a variable, D i1,j For parameters; Step 35: Based on the arrival time of each vehicle at charging station p, determine whether vehicle n on line i and vehicle m on line j have successfully transferred within charging station p, as shown in formulas (15)-(20): in, For binary variables, This indicates that vehicle n on line i can transfer to vehicle m on line j at charging station p; otherwise, the transfer fails. This is a binary variable used to linearize the if statement. is a binary variable used to linearize the "or" relationship, where ∈ represents a very small positive number; Step 36: Based on the bus transfer situation of each route in Step 35, calculate the number of passengers transferring from vehicle n on route i to bus route j at the charging transfer station, as shown in formulas (21)-(23): Where, r in,j This represents the number of passengers transferring from vehicle n on line i to bus line j within the charging transfer station. i,j This represents the number of passengers transferring from line i to line j. Step 4: With the objective function of minimizing bus operating costs and maximizing the number of transfer passengers, and with the vehicle scheduling scheme and the departure time of each bus route as decision variables, establish a passenger transfer and bus scheduling model between bus routes within the charging station. The objective function is shown in formula (24):

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